---
title: "Lateral load elements; stepwise [cut off]"
subject: "Concrete Technology and Masonry Structure"
chapter: 9
key: "semester_5/concrete_technology_and_masonry_structure:lateral-elements-stepwise-74c"
source: https://www.bctengineer.com/q/semester_5/concrete_technology_and_masonry_structure/lateral-elements-stepwise-74c
site: BCT Engineering
---

# Lateral load elements; stepwise [cut off]

Concrete Technology and Masonry Structure · Chapter 9: Masonry structures under lateral loads

- Asked in: 2074 Chaitra
- Answer checked by Claude Opus 5.5 (high effort) on 2026-10-14
- Page: https://www.bctengineer.com/q/semester_5/concrete_technology_and_masonry_structure/lateral-elements-stepwise-74c
- Whole chapter: https://www.bctengineer.com/md/semester_5/concrete_technology_and_masonry_structure/chapter-9

## Question

List the elements of masonry structure resisting lateral loads. Describe the stepwise [?] (the rest of the question is cut off in the scan).

## Short answer

Main resisting elements: shear walls, rigid diaphragms, cross walls, bands, and foundation. Design stepwise: calculate base shear, distribute to floor levels, allocate shear walls by stiffness, check in-plane shear and overturning, verify out-of-plane bending, and detail bands and connections.

## Answer

**Reading of the question:** the end of the question is cut off in the scan, so it is read as: "List the elements of masonry structure resisting lateral loads. Describe the stepwise load path (design procedure) for lateral loads."

#### Elements resisting lateral loads

1. **Shear walls:** load-bearing masonry walls parallel to the lateral force (in-plane shear and rocking resistance).
2. **Roof and floor diaphragms:** rigid horizontal slabs that distribute the force to the shear walls.
3. **Cross (transverse) walls, piers and buttresses:** support the walls against out-of-plane bending.
4. **RCC/timber bands and tie columns:** give box action and tie the walls together.
5. **Foundation** and plinth band.

#### Stepwise procedure

1. Find the lateral force: the seismic base shear $V_B = A_h W$ (IS 1893 / NBC 105) or the wind load (IS 875 Part 3) on the walls and roof.
2. Distribute the base shear to the floor and roof levels in proportion to $W_i h_i^2$ (weight and height of each level).
3. Transfer the force from each diaphragm to the shear walls in proportion to their stiffness (rigid diaphragm) or their tributary area (flexible diaphragm).
4. Check each shear wall for in-plane shear stress $\tau = V/(L\,t)$ against the permissible shear stress $f_s = 0.1 + f_d/6 \le 0.5$ N/mm$^2$ (IS 1905 cl. 5.4.3).
5. Check overturning and the extreme-fibre stresses (axial plus bending), with no tension in the masonry.
6. Check each wall for out-of-plane bending, spanning vertically or horizontally, with a permissible flexural tension of 0.07 N/mm$^2$ (vertical bending, M1 mortar).
7. Provide bands, corner steel and connections to complete the load path to the foundation.

```text
 Force -> Diaphragm -> Shear walls -> Foundation -> Ground
             (cross walls support walls out-of-plane)
```

## Check yourself

The answer's key points as multiple-choice questions, with the correct option and why.

1. How is seismic base shear found?
   A. V_B = W/A_h
   B. V_B = A_h W
   C. V_B = tau L t
   D. V_B = 0.1 + f_d/6
   Answer: B. Design horizontal coefficient times seismic weight. (Key point: Base shear)

2. Which check applies to in-plane shear walls?
   A. tau = V/(L t) not above f_s = 0.1 + f_d/6 (max 0.5 N/mm^2)
   B. tau = M/Z
   C. sigma = P/A only
   D. tau above 0.5 allowed
   Answer: A. IS 1905 cl. 5.4.3. (Key point: Shear stress check)

3. How is diaphragm force shared to shear walls?
   A. Equally always
   B. By wall colour
   C. In proportion to stiffness for rigid diaphragms, tributary area for flexible
   D. Only to longest wall
   Answer: C. Rigid diaphragms distribute by stiffness. (Key point: Force distribution)

4. What completes the load path?
   A. Removing cross walls
   B. Plaster
   C. Larger openings
   D. Bands, corner steel and connections down to foundation
   Answer: D. Continuous load path ensures box behaviour. (Key point: Last step)

## Related in Concrete Technology and Masonry Structure

- [Elements resisting lateral loads in masonry](https://www.bctengineer.com/question.md?key=semester_5%2Fconcrete_technology_and_masonry_structure%3Alateral-load-resisting-elements) — Concrete Technology and Masonry Structure, chapter 9, asked 6×
- [Typical damage in masonry under lateral loads](https://www.bctengineer.com/question.md?key=semester_5%2Fconcrete_technology_and_masonry_structure%3Atypical-damage-lateral-loads) — Concrete Technology and Masonry Structure, chapter 9, asked 2×
- [Design process for masonry wall under lateral loads](https://www.bctengineer.com/question.md?key=semester_5%2Fconcrete_technology_and_masonry_structure%3Adesign-wall-lateral-loading) — Concrete Technology and Masonry Structure, chapter 9
- [Common deficiency and failure under gravity, lateral loads](https://www.bctengineer.com/question.md?key=semester_5%2Fconcrete_technology_and_masonry_structure%3Adeficiency-failure-gravity-lateral) — Concrete Technology and Masonry Structure, chapter 9
- [Lateral load effect on wall with and without opening](https://www.bctengineer.com/question.md?key=semester_5%2Fconcrete_technology_and_masonry_structure%3Alateral-load-wall-with-openings) — Concrete Technology and Masonry Structure, chapter 9

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